Air flow control system for internal combustion engine



Sept. 9, 1969 I J. F cls ET L 3,465,735

AIR FLOW CONTROL SYSTEM FOR INTERNAL COMBUSTION ENGINE Filed Jan. 8, 1968 2 SheeCs-Shet 1 F|G.l

W 16 M x -/9 LLL//////// Y////)///// ///I INVENTORS JOJfP/rt'. zfflAC/S Eff/V010 A AME) ATTORNEYS Sept. 9, 1969 J. E. FRANCIS ET 3,465,735

AIR FLOW CONTROL SYSTEM FOR INTERNAL COMBUSTION ENGINE I 2 Sheets-Sheet 2 Filed Jan. 8. 1968 N mU h.

ATTORNEYS United States Patent US. Cl. 123-117 12 Claims ABSTRACT OF THE DISCLOSURE The air flow control system for internal combustion engines disclosed herein comprises a first valve which is responsive to differential pressure for providing communication between a point of low pressure on the engine and a motor which is operated by diflerential pressure. A first conduit extends from a vacuum point on the carburetor of the engine to a spark advance device and a second conduit extends from the first conduit to the first valve for operating the first valve. A second valve is provided which is also responsive to differential pressure and is connected by a third conduit to a point of vacuum on the engine which increases in vacuum during de-acceleration of the engine. The second valve is operable to apply vacuum to the first valve during de-acceleration to actuate the first valve so that the motor is connected to the low pressure during the de-acceleration.

This invention relates to internal combustion engines for motor vehicles, and particularly to a novel air flow valve for controlling the connection of vacuum operated devices to sources of vacuum associated with the engine during particular operative conditions of the engine.

It is conventional practice in automotive vehicle design to employ the air induction system of the internal combustion engine as a means of pumping air through vacuum actuated devices such as the air compressor on vehicles equipped with automatic leveling systems.

Since the vacuum actuated devices are of the re ciprocating type or operate in an intermittent manner, air flow flowing from the device into the engine air induction system is irregular. If such irregular air flow into the air induction system of the engine is permitted during idling operation of the engine, it results in an objectionable erratic engine idle.

It is therefore the object of this invention to overcome the above mentioned objection occurring with the use of conventional type vacuum actuated devices.

Another object of this invention is to provide a means for permitting air to flow through the vacuum actuated devices into the air engine air induction system during a closed throttle coast-down when the intake manifold vacuum is greater than that at engine idle.

In the drawings:

FIG. 1 is a part sectional schematic view of a system embodying the invention.

FIG. 2 is an enlarged cross-sectional view of the valve utilized in the system shown in FIG. 1.

Referring to FIG. 1, an automotive vehicle has an internal combustion engine 10, a carburetor 11, and an automatic leveling system air compressor -12 for supplying the air leveling system of the vehicle. Compressor 12 is of conventional construction such as the vacuum actuated reciprocating type of compressor. The engine also includes a typical vacuum controlled electric spark ignition system distributor D. Carburetor 11 is associated with a typical air induction system intake manifold 14 and carburetor 11 mounted on the engine 10. The air compressor, distributor, intake manifold, and carburetor 3,465,735 Patented Sept. 9, 1969 will be hereinafter described in detail only to the extent necessary to disclose the invention since their construction is well known.

As shown in FIG. 1, the carburetor 11 comprises a throttle body 15 which may be either a separate casting or integral with the carburetor, as shown, and is mounted on the intake manifold 14 by bolts 16. In the air induction system, a throttle valve plate 17 is pivoted in air passage 18 of the throttle body 15 so that its angular position can be varied thus controlling power output of the engine. With the throttle valve plate 17 in its curb idle and closed throttle coast-down position as illustrated in FIG. 1, a high vacuum is produced in the air induction system air passage 19 of the intake manifold 14 and in the air passage 18 below the throttle valve plate 17. Throttle body 15 is provided with a port 20 that is connected by a flexible conduit 21 to a T-connection 22 and a flexible conduit 23 to the vacuum control 13 of distributor D. Port 20 is positioned such that when the throttle plate 17 is closed as shown in FIG. 1, the vacuum in the manifold 14 does not communicate with the port 20. When the throttle valve plate 17 is in the position shown, the high vacuum in air passage 19 is not permitted to communicate with carburetor spark advance port 20 in the throttle body 11, thus preventing any spark advance via the vacuum chamber 13 of distributor D.

As the throttle valve plate 17 is opened, the vacuum in the air induction system under the throttle valve plate 17 decreases and uncovers the carburetor spark advance port 20 to permit a vacuum to communicate with the vacuum chamber 13 of distributor D through flexible conduit 21, T-connection 22, and flexible conduit 23. This vacuum is also provided to an air flow arrest valve 25 through a flexible conduit 26 connected to T-connection 22. Flexible conduits 27 and 28 are provided to connect with the air flow arrest valve 25 with intake manifold vacuum for purposes to be described hereinafter. Another flexible conduit 29 connects air compressor 12 and air flow arrest valve 25. The air flow arrest valve 25 is mounted in any convenient location on the automotive vehicle by bracket 30.

Referring to FIG. 2, the air flow arrest valve 25 comprises a generally cylindrical main body 31 formed with a cylindrical cavity 32 on one side of an annular web or flange 33 and a cylindrical cavity 34 on the other side of the web 33 or flange 33. A tube 35 extends from cavity 32 and conduit 26 is stretched over tube 35. A cylindrical undercut 36 is provided in the main body 31 for bracket 30. An intermediate body 37 is mounted on one end of body 31 by bending a flange on main body 31 inwardly. A sheet metal housing 39 is mounted on the end of intermediate body 37. Housing 39 is divided by a flexible diaphragm 40 into two chambers 41, 42. Chamber 41 communicates through an opening 43 with the interior 44 of body 37 and, in turn, with the cavity 32. A cylindrical plunger 45 is fixed to the flexible diaphragm 40 by washers 46. A third body 47 is fixed to the housing 39 adjacent the chamber 42 and a flexible frustoconical sealing member 48 surrounds a portion of the plunger 45 and is sealingly engaged with the body 47 by alight spring 49 interposed between the washer 46 and the sealing member 48 and urging the member against the body 47. Chamber 42 is vented to atmosphere through an opening 50. A heavier spring 51 is interposed between the other side of the diaphragm 40 and a portion of the housing to tend to urge the plunger 45 to the right bringing a sealing member 52 on the plunger 45 into engagement with a seat 53 on an insert 54 mounted within the body 47. A pipe 55 extends radially outwardly from the body 47 and flexible conduit 28 is stretched thereover to provide communication to the area surrounding the end of the plunger 45. An integral tube 56 extends outwardly from the insert 54 and the flexible conduit 29 is stretched thereover to provide communication to the area of the seat 53. Tube 35 has an orifice 57 therein for preventing vacuum applied to chamber 44 from affecting the spark advance.

The portion of the valve heretofore described may be considered as first valve means or first valve which is responsive to the idling position of the engine to cut off communication between the compressor 12 and the source of vacuum in the manifold 19. Specifically, when the engine is idling and the valve plate 17 is in the position shown in FIG. 1, 'vacuum is prevented from being directed to the vacuum spark advance portion 13 of the distributor D and also is prevented from communicating with the chamber 41 so that the spring 51 tends to hold the plunger 45 against the valve seat 53. This, in turn, prevents vacuum from being applied to conduit 29 to the compressor.

As further shown in FIG. 2, the air flow control valve 25 further includes a tube 60 extending radially outwardly from the body 31 over which conduit 27 is stretched to provide communication between cavity 34 and an opening 62 at an area on the manifold which is subject to having a sudden and high increase in vacuum during de-acceleration of the engine.

A housing 63 is mounted on the other end of the body 31 and has a flexible diaphragm 64 therein dividing the housing into chambers 65, 66, the latter communicating with the cavity 34. Diaphragm 64 supports a shaft or stem 67 by washers clamped over the inner periphery of the diaphragm within shoulders on the shaft 67. Chamber 65 is open to the atmosphere so as to apply atmospheric pressure to the other side of the diaphragm 64. A compression spring 68 is interposed between the housing and a shaped washer 69 that is retained on the end of shaft 67 by a screw 70. Threading of the screw 70 into and out of the shaft varies the spring tension. By this arrangement, the shaft is yieldingly urged to the left as shown in FIG. 2.

As shown in FIG. 2, an opening 71 provides communication between chambers 34, 44. A fiat valve seat 72, which extends substantially radially is provided at the area of juncture of opening 71 and chamber 44 and supports an annular resilient gasket 73 of suitable material such as synthetic rubber which will withstand the action of oil and combustible gases. A valve 74 is mounted on the end of the shaft 67 and has a substantially fiat sealing surface 75 that engages the gasket 73 and provides a seal. The valve 74 is swivelly mounted on the end of the shaft 67 in such a manner as to permit relative movement between the end of the shaft 67 and the valve 74 to accommodate any misalignment and insure a good seal. This swivel mount is such that when the valve surface 75 is in engagement with the gasket 73, there is no fluid leakage through the valve 74.

More specifically, the end of the shaft 67 is tapered as at 45 and is provided with a radial opening 76, the ends of which diverge outwardly toward the outer surface of the shaft 67. A pin 77 extends through the passage 76 and swivelly mounts the valve on the shaft 67. The ends of the pin 77 are press fitted to openings in valve 74 so that there is no leakage.

The portion of the valve to the left of chamber 44 as viewed in FIG. 2 may be considered as second valve means or a second valve which is responsive to the increased vacuum during de-acceleration to apply vacuum to the diaphragm 40 and open the valve so that the motor 12 is operated during de-acceleration.

We claim:

1. In an internal combustion engine having a carburetor, an intake manifold, and a motor operated by differential pressure from the engine, the combination comprising first valve means responsive to differential pressure for providing communication between a point of low pressure on the engine and the motor, a spark advance device, first conduit means extending from a vacuum point on said carburetor to said spark advance device,

second conduit means extending from said first conduit means to said first valve means for operating said first valve means to connect said motor to said vacuum source at all times except when the engine is idling and during closed throttle de-acceleration,

second valve means responsive to differential air pressure,

third conduit means extending from said second valve means to a point of vacuum in said engine which increases in vacuum during rte-acceleration of said engine,

said second valve means being operable to apply said vacuum to said first valve means during de-acceleration to actuate said first valve means so that said motor is connected to the low pressure.

2. The combination set forth in claim 1 wherein said first valve means comprises a body,

piston means reciprocable in said body,

said body having a valve seat,

a valve fixed to said piston and engaging said seat,

said seat being at the area of juncture of said connection to said motor and said low pressure,

the body having an opening on the opposite side of said piston means communicating with said second conduit means extending to said spark advance means.

3. The combination set forth in claim 2 wherein said piston means comprises a diaphragm, said spring means being operable on said diaphragm to urge said valve member against said valve seat.

4. The combination set forth in claim 2 wherein said second valve means comprises a second valve body having a chamber communicating with said chamber on the opposite side of said piston means of said first valve body,

a valve member normally closing communication between said chambers,

said third conduit means extending from said second mentioned chamber,

spring means urging said valve against said valve seat,

piston means on which said valve is mounted,

said piston means being responsive to the increase of vacuum during de-acceleration to move said valve away from said valve seat whereby said vacuum is applied to the piston means of said first valve means to actuate said first valve means.

5. For use in an internal combustion engine having a carburetor, an intake manifold, and a motor operated by differential pressure from the engine, the combination comprising a first valve means responsive to differential pressure for providing communication between a point of low pressure on the engine and the motor,

said first valve means having a passage adapted to be connected to a spark advance device and a vacuum point on the carburetor,

second valve means mounted adjacent said first valve means responsive to differential air pressure,

said second valve means having a passage adapted to be connected to a point of vacuum in said engine which increases in vacuum during de-acceleration of said engine,

said second valve means being operable to apply said vacuum to said first valve means during de-acceleration to actuate said first valve means whereby said motor is connected to said source of low pressure.

6. The combination as set forth in claim 5 wherein said first valve means comprises a body,

piston means reciprocable in said body,

said body having a valve seat,

a valve fixed to said piston and engaging said seat,

said seat being at the area of juncture of said connection to said motor and said lower pressure,

the body having said passage therein on the opposite side of said piston means which is adapted to be connected to spark advance means.

7. The combination set forth in claim 6 wherein said piston means comprises a diaphragm, said spring means being operable on said diaphragm to urge said valve member against said valve seat.

8. The combination set forth in claim 6 wherein said second valve means comprises a second valve body on said first valve body having a chamber communicating with said chamber on the opposite side of said piston means of said first valve body,

a valve member normally closing communication between said chambers,

said passage extending from said last mentioned chamber,

spring means urging said valve against said valve seat,

piston means on which said valve is mounted,

said piston means being responsive to the increase of vacuum during de-acceleration to move said valve away from said valve seat whereby vacuum may be applied to the piston means of said first valve means to actuate said first valve.

9. For use with an internal combustion engine having a carburetor, an intake manifold and a motor operated by differential pressure from the engine, an air flow arrest valve comprising a main body,

said body having a chamber therein,

a housing mounted at one end of said body,

a diaphragm dividing said housing into two chambers, one of which communicates with the chamber of the main body,

an auxiliary body mounted on said first housing and having a chamber therein communicating with the other chamber of said first housing,

said auxiliary body having a first passage adapted to be connected to a differentially pressure operated motor and a second passage adapted to be connected to a low pressure source on the engine,

said auxiliary body having a valve seat at the area of juncture of said chamber in said auxiliary body and one of said passages,

a valve fixed to said diaphragm,

means forming a flexible seal surrounding said valve and separating the chamber of said housing from the chamber of said auxiliary bory,

spring means yieldingly urging said valve against said valve seat,

said main body having a passage therein adapted to be connected to a spark advance device,

said main body having an additional passage therein adapted to be connected to a point on the engine which is subject to high vacuum during de-acceleration,

said main body having a valve seat separating the areas of the chamber which are connected to the passages of said main body,

a second housing mounted on the other end of said main body,

a diaphragm separating said second housing into two chambers,

a valve fixed to said diaphragm and adapted to engage the valve seat of said main body,

and spring means yieldingly urging said valve against the valve seat of said main body.

10. The combination set forth in claim 9 wherein said passage which is adapted to be connected to said spark advance device has an orifice therein.

11'. The combination set forth in claim 9 wherein said sealing means for separating the chamber of said first housing from the chamber of said auxiliary body comprises a generally frusto-conical flexible member.

12. The combination set forth in claim 9 wherein said valve which is adapted to seat on the seat of said main body is swivelly mounted to the diaphragm of said second housing.

References Cited UNITED STATES PATENTS 3,039,748 6/1962 Johnson 103-152 3,215,339 11/1965 Jackson 23052 3,339,830 9/1967 Graham 230-52 3,400,698 9/ 1968 Kelly.

CORNELIUS J. HUSAR, Primary Examiner 

